1. Field of the Invention
This invention pertains to a soil compaction device with a support for a starter battery.
2. Description of the Related Art
These types of soil compaction devices, such as vibration plates known from DE-U-298 04 047 as well as vibration tampers or vibration rolls are commonly driven using an internal combustion engine that is started using an electric starter fed from a starter battery. These batteries are mainly grid plate accumulators that are designed for loads encountered in the operation of automobiles in street traffic. In the operation of a soil compaction device, however, very high acceleration loads arise that are transmitted to the battery depending on the type of receptacle for the battery in the device, so that the grid structure of the batteries can experience damage quickly. For this reason, special vibration-free batteries were developed, which, however, are very expensive. On the other hand, it is possible to store the batteries softly in the receptacle on so-called damping pillows, which are plates made of elastic material. However, even in this case, unacceptably high acceleration loads are conveyed onto the batteries. In addition, it takes a lot of work to fasten the damping pillows in the receptacle.
Similar problems exist in other oscillatory equipment such as for blade smoothers to smooth out concrete, joint cutters or generators.
DE 195 40 927 A1 illustrates a counteracting oscillator for an automobile in which a vehicle battery serving as the counteracting mass is held in a cage that is supported by elastic support elements on the walls of the vehicle. The battery produces a counter-oscillation due to its inertia, and this is superimposed onto the vehicle oscillation, thus tempering the vehicle oscillations.
A similar design is known from DE 43 40 007 A1. In sustained operation, vehicle oscillations are considerably weaker than the oscillations that occur in soil compaction devices carrying a heavy oscillator.
Another counteracting oscillator arrangement for automobiles is known from JP-A-02197446 in which the mass of a starter battery is used as a damping mass to temper vehicle oscillations.
JP-A-10016689 discloses an oscillation-insulating carriage for a starter battery that can be inserted into a closed box that in turn sits on springs to dampen weak impacts. In order to prevent the destruction of the battery in case of a vehicle collision, an airbag is located in the main direction of motion of the vehicle separated from the box. This airbag is inflated in an accident and cushions the battery and the box.
This invention seeks to provide a soil compaction device in which excessively strong effects of acceleration loads on the starter battery is prevented without requiring a large amount of design work.
The solution of the objective is given in the features of patent claim 1. Advantageous embodiment forms of the invention are found in the subordinate claims.
According to the invention, an oscillatory piece of equipment, in particular a soil compaction device, is provided with a receptacle provided at an upper side of the soil compaction device, a cage to hold a battery that can be placed in the receptacle, a gap designed between at least one external side of the cages and at least one internal side of the receptacle and at least one spring-damper element located inside the gap that is not fastened to the receptacle.
The advantage to this is that the battery can then be very easily pulled out of or inserted into the receptacle together with the cage that serves as a box. No additional locking means is required. It is preferred that the spring-damper elements are fastened to the cage here. However, they can also be placed loosely into the gap between the cage and the receptacle.
It is advantageous if a number of spring-damper elements are fastened to at least one external side of the cage. This makes it possible to prepare the cage with the battery contained in it outside the receptacle and to equip it with the spring-damper elements suited for the respective equipment. Then, the cage can be placed into the receptacle.
Since the spring-damper elements do not have to be fastened to the receptacle, the receptacle permanently connected to the equipment can be designed by means of a simple recess needing no further design measures.
The oscillatory damping function is assumed exclusively by the cage and the spring-damper elements fastened to it so that the battery placed into the cage is protected against high acceleration loads.
An advantageous embodiment form of the invention is characterized in that the external sides of the cage enclose at least one floor plate and a number of side walls, to which at least one spring-damper element is fastened, respectively. This makes it possible to take up oscillations that are exerted by the receptacle onto the cage from nearly all spatial directions.
It is advantageous if the spring-damper elements are made of an elastic rubber material. They can be designed in any manner suitable to produce the desired spring and damping characteristics. Moreover, the spring-damper elements can be exchanged at the cage so that the cage can be adjusted for other uses. The design of the spring-damper elements should be done, in particular, so that the characteristic frequency of the cage in the receptacle is smaller than the exciting frequency. In the process, excessive oscillation amplitudes by the battery must be prevented by selecting the right damping in the spring-damper elements and by appropriately attaching the spring-damper elements.
A very advantageous embodiment form of the invention is characterized in that the cage is made of two separated halves, between which the battery can be placed. This allows the same cage to be adjusted to batteries with different sizes since common starter batteries vary in design length for the most part depending on their capacity, whereas their height and width remain constant. The halves of the cage can thus be used in different equipment with different starter battery lengths without having to modify the cage halves themselves.
For improved handling ability, it is very useful if the cage halves or the cage have carrying grips.